The present disclosure relates to an image pickup device. In particular, the present disclosure relates to a solid-state image pickup device in which an Optical Black pixel area is light-blocked by a light blocking film, and a method of manufacturing the solid-state image pickup device. In addition, the present disclosure relates to an electronic apparatus using the solid-state image pickup device.
A Charge Coupled Device (CCD) type solid-state image pickup element used in an area sensor, a digital still camera or the like is mainly composed of plural photodiodes, vertical transfer portions, a horizontal transfer portion, and an outputting portion.
A photodiode is a photoelectric conversion portion for subjecting an incident light to photoelectric conversion. Plural photodiodes are formed on a semiconductor substrate. The vertical transfer portion is an area in which the electric charges supplied from the photodiodes are received and are then transferred. The vertical transfer portion is composed of a vertical transfer path formed above the semiconductor substrate, and plural vertical transfer electrodes disposed adjacent to one another on an upper portion of the vertical transfer path. In the vertical transfer portion, the vertical transfer electrodes are successively driven, thereby transferring the electric charges through the vertical transfer path in a vertical direction. On the other hand, the horizontal transfer portion is an area in which the electric charges supplied from the vertical transfer portion are received and are then transferred. The horizontal transfer portion is composed of a horizontal electric charge transferring portion formed above the semiconductor substrate, and plural transfer electrodes disposed adjacent to one another on an upper portion of the horizontal electric charge transferring portion. In the horizontal transfer portion, the horizontal transfer electrodes are successively driven, thereby transferring the electric charges through the horizontal electric charge transfer path in a horizontal direction. The outputting portion is formed in a final stage of the horizontal transfer portion, and converts the electric charges transferred thereto from the horizontal transfer portion into a voltage, thereby outputting the resulting voltage.
In such a CCD type solid-state image pickup element, in recent years, for the purpose of making a large field angle and high-speed rate transfer possible, it is required to reduce a resistance value of the transfer electrode. At the same time, there is caused a problem that along with an increase in the number of pixels, a light receiving area per one pixel is reduced, and a quantity of received light is reduced, thereby reducing the sensitivity. A structure including a light blocking film serving as a wiring as well for control, and connected to a vertical transfer electrode is proposed for the purpose of the reduced resistance value, the increase in the light receiving area, reduction in resistance value of a wiring layer and the like. This technique, for example, is disclosed in Japanese Patent Laid-Open Nos. 2000-81402 and 2009-252840.
In addition, in general, a pixel area of the CCD type solid-state image pickup element includes an effective pixel area and an Optical Black (OB) pixel area. In this case, the effective pixel area outputs the electric charges generated through the photoelectric conversion for the received light. The OB pixel area is used to obtain a signal which is used as a reference of the black level. In the OB pixel area, the entire light receiving areas of the pixels are covered with a light blocking film. Japanese Patent Laid-Open No. Hei 11-186204 describes a structure in which a light blocking film formed in an effective pixel area and a light blocking film formed in an OB pixel area are formed integrally with each other to be electrically connected to each other. In this case, an opening portion is formed in the light blocking film right above a photoelectric conversion portion in the effective pixel area, and the light blocking film is formed above the photoelectric conversion portion so as not to form an opening portion in the light blocking film in the OB pixel area.